Unison Research SH
 
Back in March I had the opportunity to listen to the Unison Research SH – Class A Valve Headphone Amplifier at the local Raleigh, NC Meet.  Shane from Night and Day Audio had the prototype and he brought it to the meet.  I absolutely fell in love with two things that day. The Audeze LCD-XC with Wywires red cables, and the Unison Research SH.  I immediately told Shane that I was interested in getting one when they came available.
 
In June, Shane gave me the opportunity to keep his prototype for a couple days at my house to make sure I still wanted to buy it.  I listened for a couple of blissful days to the SH my TH-900. That cemented it for me.  YES!  Please and thank you!  I do want an SH of my own!  I put one on order.  Oh, yeah.  And I bought a pair of LCD-XC at the same time.
 
Unison Research has been busy building the production model and getting them shipped.  Shane worked out a deal to have mine sent to me overnight when the container got unpacked.  They shipped it last Friday, and it arrived on my doorstep 1:30pm on Monday.  Quality service from Shane and his distributer!  Thank you guys very much!
 
So it is entirely possible that I have received the first production model in North America.  At least that is what I’ve been told.  I will take that distinction!
 
Here are some specifications from the Night and Day Audio website:
 
Unison Research SH – Calss A Valve Headphone Amplifier
All tube headphone amplifier and DAC
MSRP $1695 (usd)
 
A world class all tube EL-84 output tube based headphone amplifier operating in pure Class A output, combined with a stellar USB DAC module capable of all high rez PCM formats and 1X and 2X DSD playback! 
 
Inputs:
1) Analog RCA single ended input (directly feeds the 12AX7/EL-84 all tube headphone amplifier)
2) USB (Class 2.0 input feeds the onboard DAC board that handles up to 32/384K PCM or 1X or 2X DSD.  Native Mac plug and play support.  Windows computers require driver installation)
 
Outputs:
1) Qty. 2 6.3mm / 1/4″ single ended headphone jack – both outputs can be run concurrently to feed two sets of headphones simultaneously.
 
High / Low sensitivity switch for more precise gain adjustment to match connected headphone capabilities.
The Unison Research Unico SH measures 22.5 x 12.6 x 32.2 cm and weighs in at 13.2 pounds unboxed.
It is available in two finish options.  The main body of the unit will always be black.  But the front faceplate can either be black with cherry wood inserts around the output connectors, switches and volume knob, or it can be cherry wood faceplate with black inserts around the output connectors, switches and volume knob.
 

Unboxing:
The box is pretty solid and the insides are well cushioned with partitioned Styrofoam.
 
There is not really very much included in the box.  You get and Amp, a power cord, and a 1/4 inch to 1/8 inch adaptor.
 
It is stated to be 13.5 pounds and feels extremely solid.
 
It comes in two different faceplate styles.  Cherry wood with black inserts, and Black with Cherry inserts.  The inserts are around the Volume knob and the headphone jacks.  Mine is the black with cherry version.  In person, it is understated, classy, and to me - beautiful.
 
The volume knob is fluid and smooth.  It has the right amount of resistance, so that it doesn’t spin like the Price is right showcase wheel.  Zero would be at 7:00 on the clock dial, and Max is at 5:00 on the clock dial.
 
One of the most distinguishing things about the Unison Research SH is that it provides two 1/4 inch headphone outlets.  So now you can share your obsession with your wife/husband.  Or share your hobby with your buddy and get him/her obsessed.  I’m looking forward to a Thin Lizzy session with my buddy. 
 
There are two “Headphone Sensitivity” settings.  With the TH-900, which are fairly easy to drive, the “High” sensitivity setting has me at volume of about 1:00.  “Low” sensitivity setting has me at about 11:00.  Previously with the prototype, and now with the production model, I have chosen the “Low” sensitivity setting. I like having a little more headroom. 
 
There is an oval slit in the top and it is covered with silver bars.  This is where you can look in and see your tubes.  It’s not really set up as a visual enhancement where it is showing off the tubes.  I believe it is for ventilation, and so you can see if your tubes are on.
 
The power switch is on the right (long) side, as you look at the face.  It is about 5 inches back from the face.  As with the rest of the SH, it is understated and low key.  Twice, already, I have flipped the sensitivity switch thinking I turned it off.  Then I come back later and see the green light still illuminated on the front.  Yes. Sometimes, I am a dumb@$$.  The green power on light is directly between the High/low sensitivity switch and the Line/USB switch.  And it is just the right amount of brightness.
 
The only thing that I don’t like so far is that there are three feet on the unit instead of four.  Two in the front corners, and one in the middle rear.  I noticed this on the prototype as well.  It really isn’t too much of a problem, but if you press down on one of the rear corners, it will wobble.
 
Not much else to say.  Here are some pictures.
 




Edit: Added picture of rear of unit.

Initial impressions:
Of course the tubes are not burned in yet, so my initial impressions will be short and sweet. 
 
I have been reconnecting with my Beatles recently and Abby Road, Rubber Soul, and Revolver sound full and deep on the low end.  I find myself listening (noticing) more of Paul’s bass lines on this session.  Highs are crisp and clear.  You can hear Ringo’s cymbals and percussive bells (sleigh bells). 
 
I’m using the RCA inputs.  My kit is 16/44k FLAC > iBasso DX 50 > Audio quest 1/8” to RCA Green > Unison Research SH > Fostex TH900.
 
I will put some hours on the tubes, and try it out and give more impressions with my Fostex, and the LCD-XC.  More to come.
 

Review:
(reserved)

Reserved

Is it possible to post a pic of the rear ? So it dos not have a coax digital input ?

punit said:

Is it possible to post a pic of the rear ? So it dos not have a coax digital input ?

Click to expand...

I will post a pic of the rear when I get a chance.  I'm at work now.
And No.  There is NO coax digital input.  I WISH!!!  It has RCA Aux input, and USB input with a built in DAC.  I would love a digital coax input.

punit said:

Is it possible to post a pic of the rear ? So it dos not have a coax digital input ?

Click to expand...

Rear of unit picture added to unboxing post.

Nice reading from "Sir First Owner". Congratulations !
 
Only USB input is the same story as on my UR Unico CD player and it is - luckily - of no importance to me as I need SH only as an analog headphone amplifier.
 
It would be nice to have a choice of  DAC-less SH, as is the case with Triode 25 where DAC is optional.

I wish I had spent more time with this beautiful amp at the meet. I'm hoping that will be remedied once I get my 900's back

jjz109 said:

Nice reading from "Sir First Owner". Congratulations !
Only USB input is the same story as on my UR Unico CD player and it is - luckily - of no importance to me as I need SH only as an analog headphone amplifier.
It would be nice to have a choice of  DAC-less SH, as is the case with Triode 25 where DAC is optional.

Click to expand...

Thank you kindly sir.  Yes.  DAC less would be a nice option.  But I'm still trying to figure out ways to make it work for my situation.  So far, I'm just enjoying it analog.

afghan vet said:

I wish I had spent more time with this beautiful amp at the meet. I'm hoping that will be remedied once I get my 900's back

Click to expand...

Yes.  When you get your 900s back we can A/B them right from the same amplifier, since we have two 1/4" outputs.  If the mod doesn't do anything crazy for the spl level, this should work perfectly!

Updates? please.

I can give a little update  
 
I met up with Fester to compare my modded Fostex TH900 to his stock TH900's with the Unison Research amp. Very cool capability of this amplifier to power two single ended headphones at the same time - made A/B comparison a breeze. So we had his iBasso hooked up directly to the UR, and that was really good. Then, for kicks - we hooked up the UR to the Vega DAC running from a cambridge dvd player - a Very good combo! I really appreciated the warm tubey sound from this amplifier - and with the Vega - the UR had a ton of headroom. 
 
Fostex (not pictured) and Grados connected to the UR
 

 
 

 

 
Unfortunately the HE-6's were balanced, so we didn't have the ability to see if the Vega/Unison Research could adequately power those beasts, but I put it up there for a photo anyway.....well, a cell phone pic......
 

afghan vet said:

  I can give a little update  
...

Click to expand...

Thanks for comments!
 
Asking importers to demo.

During our mini meet, we found that the Unison Research SH can be helped by the source, for sure.  
 
First setup was the iBasso DX 50 (FLAC) > Line out > UR SH > TH900 sounded grand.  There was definitely enough power from the tiny iBasso to give the Unison Research a great front end and plenty of headroom.  This is my normal setup.  Except I will change the TH900, for LCD-XC, or Grado RS1i.
 
Second setup was a laptop running Media Monkey FLAC > Schitt Gungnir DAC >UR SH > TH900.  I listened to the same FLAC songs back and forth between the DX50 and the Gungnir.  There was not quite enough front end to for the UR from the Gungnir.  Couldn't get enough headroom from that setup.  Definitely left wanting more.
 
Third was, as Afghan Vet said above, his Cambridge Audio DVD > Auralic Vega > UR SH > TH900.  Audio bliss.  He played some songs that just dropped my jaw wide open.
 
So I'm not entirely sure what is going on with the DX50 vs the Gungnir.  I just looked up the spec sheets (quickly) and it says that the DX50 line out is 1.5v, and the Gungnir is up to 2.0v.  So there must have been something in the chain that needed to be tweaked.  The laptop to gungnir was the first time that setup had ever been used.  My laptop and TomNC's Gungnir.  I tend to use portable transport (dx50) and not really much of a laptop music user.  Except for ripping and organization.
 
Vega specs show up to 4.0v.  No issues there.  
 
So far, still loving the UR SH and my setup.    Thanks for asking.